A Cardboard Bridge That Supports 297 Times Its Own Weight!

08.03.12 - The second edition of the “Cardboard Bridge Contest” took place Monday at EPFL. The participants had access to no more than 100 grams of cardboard and white glue to create a bridge reaching one meter in length.

The tension was palpable throughout the room. Slowly, doing their best not to tremble, the participants gradually added weights, then nails, to the bucket attached to their ephemeral work: a model bridge. Its fatal destiny that night was to collapse from the load. Above the stage a giant screen enabled the spectators – and especially the competitors – to catch every second of the spectacle.

Last Monday was the second time that the “Cardboard Bridge Contest” was organized by EPFL, with the support of the School of Architecture, Civil and Environmental Engineering (ENAC). “We plan to repeat it each year,” says Alexandru Moraru, director of the 2012 edition. Previously, a similar contest had been hosted by the school’s alumni association, A3.

The competition is open to all, even if it is spearheaded by the interest of students in the ENAC School – architects and civil engineers leading the pack. The principle is simple: to construct a bridge whose expanse reaches exactly one meter, using only white, brown or gray cardboard, along with white glue. The final weight of the bridge must not exceed 100 grams.

At the competition, the teams place their construction on a support, hang a bucket, then proceed to add weight until the breaking point. “We measure the resistance by dividing the supported weight by the weight of the bridge itself,” explains Alexandru Moraru. “An ultra-light structure therefore has a good chance of success.” A jury ranks the bridges as well for their aesthetic value.

Over 27 Kilos on the Scale! “The Tourists” stole the show this year. Valerio Santoni and Ken Jun Triponez, both architecture students, improved upon an idea presented at last year’s competition. They did well to adopt it: their work, weighing 93 grams on the scale, bore a load reaching 27.67 kilos before collapsing – representing nearly 300 times its own weight!

In addition to being fun, this contest is genuinely worthwhile pedagogically. It permits, at hardly any cost, to experiment with audacious structures and forms and to open minds to new approaches in building and construction. This is not without practical interest in the world: today, the heaviest burden carried by a concrete highway bridge is not the vehicles that traverse it, but rather, its own weight!